The heatmap is not resampled. In v5 we do however perform some optimisations internally (such as not bothering to write to a pixel more than once).

You can – if you have source code access – modify our heatmap source for direct access to the RenderSurface. In v5 we basically draw to texture then blit that texture to the screen. However other than that, it’s not possible to modify how the heatmap draws.

In fact, you might be able to achieve this by overriding one method and customizing the drawing.